Triple-tracking!! 2 monos and one stereo with delay separation

With delay you always run the risk of having phase issues. I think what you supposed to do with triple tracking is left/right/center (no delay)... I believe black album and enemies of reality (nevermore) was done that way.
 
Agreed. I've experimented with stuff like this and it causes much more problems than it solves.

Youre much better off just quading or tripling. At the moment I'm gravitating towards triple with the centre pretty heavily high passed and blended with the low mids of the bass, and mixed low.
 
I'd maybe try two different cabs/impulses then. I've gone down the delay path and IME you get phase stuff under 10ms and then it start to lean (you'll only perceive the first one you hear). Obviously if it works for you ignore me and do it.
 
On the stereo-widened track, I'd EQ the left/right channels separately. Not too different, not too similar.
Maybe some multiband comp dedicated to each channel as well, with medium attack and release times ;)
 
Don't do the stereo middle track. Just duplicate your left and right guitars and reverse the panning, chuck a 10-20ms delay on each one and flip phase. Widener.
 
IMO double track with diferent impulses/cab sounding one brighter than other but not too much diferent.
Take a good bass sounding like shit (Add a touch of chorus in the bass with a 600 Highpass).
;)
 
The delay separation trick only "kind of" works for me atleast. I always feel like the track that has been delayed is lower in volume since the transients come first from the original track. However I did experiment with this thing when creating a doubling effect for my live sound with the Axe-Fx.

To get it really working you need to have a delay on both sides that varies from 5-10ms with a controller like f.ex. on the Axe-Fx I use the LFOs. This way both the L and R side get the first transient from time to time. But that's not all. Add chorus to one of these tracks and set mix to 100%. What this will do is slightly change the pitch of the other side but not over the top... it should still sound like there's no chorusing on it.

This is an effective way to get doubled guitars as a single guitarist. In a recording situation I would say that it's just lazy not to track the fourth track.